I believe the INT25 is basically the XA25 with a 6db gain buffer in front of it for a preamp section, so you can also use XA25 reviews as your guide.
I use Nelson's First Watt SIT amps with my Coherent speakers (which are also high efficiency like your Klipsch) and love it, so I would guess that the INT25 and Heresy IV would be a killer combo. Steve Huff reviewed the INT25 with Klipsch.